I ran across a great article about light and sleep. The original article is by Dr. Roizen and Dr. Oz and states that there is a blue light that is similar to that of a sunrise. If you use this light early in the morning or in the middle of the day, it tells your body that it is “awake” time.
This blue light helps with your internal body clock and melatonin levels. The idea of it is that your body will get signals telling it that it is time to be awake and that in turn, will let your body know that it is time to sleep later on. You can read the original article here.
It may also be worth noting here that it has been said that any light in the room can interfere with sleep. That even includes your digital alarm clock. It’s best to sleep in a dark room without those electronic lights on display. Try to turn over your alarm clock so you don’t see it and cover up any other little lights. You never know what little thing might help.